Development to reduce the size of an X-ray generator has been progressed because of requirement for space-saving, energy-saving, portability, minimization of exposure to an X-ray and the like.
For example, an X-ray generator having a small X-ray tube using a field emission carbon nanotube cathode and a high-frequency coaxial cable for applying high-voltage ultra-short pulses to the X-ray tube has been proposed (refer to Patent document 1).
Also an X-ray generator that irradiates a copper piece with electrons emitted from a pyroelectric element and that emits an X-ray from the copper piece has been proposed (Non-patent document 1).
Also Non-patent document 2 may be referred to as a technology related to the present invention.